Also From California Report

Scientists Hunt Urchins to Save Kelp

Purple sea urchins eat kelp spores trying to take root on the sea floor. Urchins grew dominant after people hunted out sea otters and other predators in 1850.

Imagine a grove of trees you can sail down into, 80 feet tall, filled with wildlife. In the Pacific Ocean, that's called a kelp forest. Southern California has lost vast amounts of these underwater forests. In order to restore kelp in a patch of ocean off the Palos Verdes Peninsula, scientists are taking the fight to prospering sea urchins. Reporter: Molly Peterson